.svg-demo {
  padding: 100px;
  --stop-color: red;
  color: var(--stop-color);
  display: inline-block;
  width: 100px;
  height: 100px;

  svg {
    width: 100%;
    height: 100%;
  }
}

@keyframes spin {
  0% {
    transform: rotate(0deg);
  }

  100% {
    transform: rotate(360deg);
  }
}

.circle {
  position: relative;
  width: 100px;
  height: 100px;
  animation: spin 1s linear infinite;
}

svg {
  animation: spin 1s linear infinite;
}

.circle-left {
  position: absolute;
  top: 0;
  left: 0;
  width: 50px;
  height: 100px;
  border-radius: 100px 0 0 100px;
  background: linear-gradient(to bottom, rgb(51, 51, 51), rgba(51, 51, 51, 0.2));
}

.circle-right {
  position: absolute;
  top: 0;
  right: 0;
  width: 50px;
  height: 100px;
  border-radius: 0 100px 100px 0;
  background: linear-gradient(to top, rgba(51, 51, 51, 0.22), rgba(51, 51, 51, 0));
}

.circle-inner {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 80px;
  height: 80px;
  border-radius: 40px;
  background-color: #fff;
}
